This invention relates to a trough bridge which is composed of bridge sections, each having a roadway deck segment and side wall segments. At least one side wall segment is articulated to each side of a roadway deck segment.
Since the side walls of a trough bridge of the above-outlined type have to take up large upper chord forces when the bridge is loaded, the side walls have to be secured against outward buckling. In permanent bridges such a securement is generally effected by providing the upper chord with frame-like stiffening structures at defined distances.
In mobile bridges which are composed of individual components, the stability of the side walls is ensured by arranging, at predetermined distances, stabilizing struts which support the upper chord. Such structures have the disadvantage that they are expensive and take up additional volume in transport.
As disclosed, for example, in published European Patent Application 0 290 405, it is known to form the side walls of mobile bridges as box-like structures. For connecting the roadway deck segments with the lateral walls, eyelets are provided which are arranged in pairs. In this construction one eyelet carried by the roadway deck segment and another eyelet carried by the side wall segment form a hinge which allows the bridge components to be folded together. The eyelet carried by the roadway deck segment is in alignment with the eyelet carried by the side wall segment in the folded condition of the bridge components. A pin may be inserted through the eyelets and thus a rigid connection of the two components is obtained. Such a bridge too, is involved with significant expense and requires a substantial volume for transport.
German offenlegungsschrift (application published without examination) 34 26 397 discloses a hinge for a folding articulation of two bridge components in which each bridge component is provided with eyelets. A pin is inserted through the eyelets of two adjoining bridge components, and the length of the pin is so designed that one half is received in one eyelet and the other half is received in the adjoining, other eyelet. Such a hinge is not adapted to transmit tension forces.